We expect to continue to study the inheritance and development of organelles in Euglena, particularly the mitochondrion and chloroplast to determine: 1) The various morphological and physiological parameters of organelle development; 2) The source of the molecular building blocks for development and 3) The source of the genetic information for organelle development. To these ends we will continue our studies of pyrenoid differentiation, light-induced ribosomal RNA synthesis, antibiotic sensitivity of various developmental parameters, mutants resistant to these antibiotics, mutants which are blocked at various stages in development, etc.